Distribution and growth of autumn olive in a managed landscape

Invasions by exotic plant species result in significant challenges for forest managers. Disturbance and increased light have been shown to facilitate the successful establishment and invasion of exotic, invasive plant species. Several studies have sought to determine which key factors lead to greater abundance of exotic, invasive plants on certain sites and this information is important for determining the likelihood for exotic plant invasions at broad scales. Site characteristics that may promote autumn olive (Elaeagnus umbellata) were studied. Our goal was to identify variables associated with forest road edges most important in explaining autumn olive abundance and growth. The objectives were to: 1) investigate whether southern aspects have greater abundance and height of autumn olive than other aspects, 2) determine if there is a negative relationship between the abundance and height of autumn olive and the abundance and height of native species, 3) determine if the relationship between autumn olive abundance and height and other invasive species abundance and height is positive and 4) document other site factors significantly related to the success of autumn olive. Larger autumn olive were more dense and patches of autumn olive were deeper on certain forest-road edges. Autumn olive height and abundance were positively related to both native and exotic, invasive plant height and abundance. Road canopy cover, slope, elevation, road opening width and road type were found to be important for autumn olive establishment and success. These factors will be investigated for future use in producing GIS based risk maps to assist managers in exotic, invasive species control